Summary Type 2 diabetes mellitus (T2DM) is associated with both poorer clinical outcomes during the COVID-19 pandemic and an increased risk of death in such hospitalized patients. While the role of glucose control has been emphasized to improve the prognosis, the impact of different glucose-lowering agents remains largely unknown. Metformin remains the first-line pharmacological choice for the management of hyperglycaemia in T2DM. Because metformin exerts various effects beyond its glucose-lowering action, among which are anti-inflammatory effects, it may be speculated that this biguanide might positively influence the prognosis of patients with T2DM hospitalized for COVID-19. The present concise review summarizes the available data from observational retrospective studies that have shown a reduction in mortality in metformin users compared with non-users, and briefly discusses the potential underlying mechanisms that might perhaps explain this favourable impact. However, given the potential confounders inherently found in observational studies, caution is required before drawing any firm conclusions in the absence of randomized controlled trials.

中文翻译：

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二甲双胍和 COVID-19：从细胞机制到降低死亡率

摘要 2 型糖尿病 (T2DM) 与 COVID-19 大流行期间较差的临床结果以及此类住院患者死亡风险的增加有关。尽管人们强调血糖控制对于改善预后的作用，但不同降糖药物的影响仍然很大程度上未知。二甲双胍仍然是治疗 T2DM 高血糖的一线药物选择。由于二甲双胍除了降血糖作用外，还发挥多种作用，其中包括抗炎作用，因此可以推测，这种双胍可能会对因 COVID-19 住院的 T2DM 患者的预后产生积极影响。本简明综述总结了观察性回顾性研究的现有数据，这些数据表明，与非使用者相比，二甲双胍使用者的死亡率有所降低，并简要讨论了可能解释这种有利影响的潜在潜在机制。然而，考虑到观察性研究中固有的潜在混杂因素，在缺乏随机对照试验的情况下，在得出任何明确的结论之前需要谨慎行事。